Display a warning there's a palette defined in an XBin file and the

terminal doesn't support loadable palettes.
If fonts aren't supported in the terminal and there's fonts in the XBin,
display a warning about that too.
Updated paren style to match ec's, being polite an' all.

xtrn/ansiview/ansiview.js

@@ -135,8 +135,20 @@ function drawFile(file) {
 			image = xbin.read(f);
 		}
 		f.close();
-		if (image.font && image.font.length && image.charheight != cterm.charheight(console.screen_rows)) {
-			alert(format("Warning: file intended for a different char height (%u), font not used.", image.charheight));
+		var warning = '';
+		if (image.font) {
+			if (cterm.supports_fonts() == false)
+				warning += "Warning: your terminal does not support loadable fonts; font not used.\r\n";
+			else if (image.font.length && image.charheight != cterm.charheight(console.screen_rows))
+				warning += format("Warning: file intended for a different char height (%u); font not used.\r\n"
+					,image.charheight);
+		}
+		if (image.palette) {
+			if (cterm.supports_palettes() == false)
+				warning += "Warning: your terminal does not support loadable palettes; palette not used.\r\n";
+		}
+		if (warning.length) {
+			alert(warning);
 			console.pause();
 		}
 		cterm.xbin_draw(image);